The present invention is a nutrient separating filter basket for a storm water drain system. A filter basket is installed within a storm water drain pipe system and receives storm water runoff therethrough and collects organic materials, such as grass clippings, leaves and tree stems, therein.
Drain water, which is frequently laden with trash, grass clippings, tree leaves and stems, sand, gravel, and other forms of sediment, is collected from streets, parking lots and other areas into a storm drain inlet where it is directed into a storm water drain pipe system. The drain water laden with trash, leaves, grass clippings, sand and gravel collected from the streets is fed through an entrance into a storm water catch basin and into a lake or retention pond. The retention pond can tolerate a certain amount of grass clippings and leaves collected from parking lots or along the street but debris left in the water for a long period of time decays and allows a buildup of soluable nutrients, such as nitrates and phosphates, to accumulate in the water. Thus, it is desirable to remove organic debris from the water collected from the drain water before it enters into lakes and retention ponds.
The present filter basket is added directly to the storm water drain pipe system for collecting trash, leaves, grass clippings, tree stems, and other organic matter in a manner to dry these materials before they can rot in the water and release soluable nutrients into the water. Sand, gravel, or other non-organic sediments can pass through the basket screen walls and collected within a drain water catch basin. The present system provides for an easily cleaned filter basket which allows rapid cleaning of the filter basket and filter box in situ.
In my prior U.S. Pat. No. 6,428,692 for an In-Line Storm Water Drain Filter System an in-line storm water drain filter and baffle box is installed within a storm water drain pipe to direct storm water runoff through the storm water drain pipe and through the filter and baffle box prior to the storm water drain water passing through an outfall into a lake, pond or retention area. This patent is for a filter system and includes a housing having an inlet and outlet and a plurality of chambers formed therein. The housing cover allows for access into a housing. A plurality of filter screens are mounted over each of the plurality of housing chambers for collecting trash from the storm water passing therethrough.
The present invention is an improvement to this prior U.S. patent and allows a screen filter basket to receive the inflow of storm water and to collect all of the larger debris while letting the water pass along with sand and grit to pass through the screen and into a baffle and settling box. A plurality of doors in the filter basket allow for the in situ cleaning of debris therefrom and from the settling box therebeneath.